And so, his award-winning journey from the village lights of Knockanure to the bright lights of Los Angeles began. But his native roots have remained firm every step of the way.
His first film, Pilgrim Hill (2013), depicting the life of an Irish cattle farmer living alone with his invalided father on a rundown farm in the west of Ireland, saw Barrett highlight rural isolation. He won the Rising Star Award at the IFTAs (Irish Film and Television Awards) for his debut.
His follow-up, Glassland -starring Hollywood actress Toni Collette and Irish star Jack Reynor and telling the story of a son desperately trying to protect his troubled, alcoholic mother - proved he wasn't a one-hit wonder.
However, the 28-year-old says his latest series, Smalltown, allowed him to go "a step further" and delve into the biggest issues - including emigration, loneliness and loss - that have crippled farm families, and his own generation, since the economic crash in 2008.
The series tells the story of Conor, a 20-something who is forced to leave the family farm and emigrate to London for a better life.
Years later he returns home, expecting things to be the same, but much is changed and he must deal with the reality of losing a parent.
"I wanted to shine a light on the impact of emigration and the crises farm families all over the country have faced over the last eight years," says Barrett.
"I definitely think that the farming class in Ireland is having a tough time and sometimes you have to see the problem to figure out what it actually is. That is the power of drama and TV to bring it into people's homes so they can see themselves," he told the Farming Independent.
"Whether you had to move to Dublin or London or Australia or America, the loneliness and home sickness and waiting for that dreaded call that one of our family has been sick or is after being killed, these are things we all think about when we are away and that's definitely what my generation went through," he said.
According to ratings, almost all of Munster and Connacht tuned in to watch the three-part series, starring Pat Shortt, on TV3 earlier this month.
Barrett, who premièred his new film, Brain on Fire, starring leading actors Chloë Grace Moretz and Charlize Theron last week at the Toronto Film Festival, contends that Irish film and media is "ignoring the real heartland".
"People are reading the reality of it (Smalltown), feeling the honesty and they are seeing themselves on screen. That's why The Riordans and Glenroe were so important because there was an outlet for people to see themselves," he said.
"Today, the media is dominated by urban stories and urban politics. There is a big gap and the real farming class is ignored. Ten minutes of Prime Time a couple of times a year doesn't cut it. Farming in rural Ireland is what actually keeps it going, and it definitely needs more respect - and it needs to be talked about. Smalltown isn't everyone's story but it adds to the conversation," he said.
He adds he has received thousands of emails and letters from country people thanking him for telling their story.